(1) Field of the Invention
This invention relates to a substrate treating apparatus and a substrate treating method for treating, such as cleaning and etching with treating liquids or solutions, substrates such as semiconductor wafers or glass substrates for liquid crystal displays (hereinafter called simply substrates), and thereafter drying the substrates with solvent vapor.
(2) Description of the Related Art
A conventional apparatus of this type includes a treating tank for storing deionized water, a chamber enclosing the treating tank, a holding mechanism for vertically moving substrates between a treating position inside the treating tank and a drying position above the treating tank, a vapor generator for generating a vapor of isopropyl alcohol (IPA), nozzles for supplying the vapor of isopropyl alcohol into the chamber, and an exhaust pump for exhausting gas from the chamber (see Japanese Patent No. 3585199, for example).
In the apparatus of such construction, the holding mechanism holding substrates is first moved to the treating position to clean the substrates as immersed in deionized water. Then, a vapor of isopropyl alcohol is supplied from the nozzles to fill the chamber with a solvent atmosphere. Subsequently, the holding mechanism holding the substrates is moved from the treating position to the drying position. Next, the exhaust pump is operated to exhaust gas from and decompress the chamber, and the vapor of isopropyl alcohol adhering to the substrates is dried to dry the substrates.
The conventional apparatus with the above construction has the following drawback.
With an increasingly refined process, the conventional apparatus can have a high concentration of isopropyl alcohol in the vapor supplied into the chamber. In such a case, the concentration of isopropyl alcohol in the exhaust gas from the exhaust pump becomes high, which poses a problem of imposing a load on exhaust equipment (utility) of the user.